The invention relates to a fuel injection pump for internal combustion engines. In such a fuel injection pump, known from U.S. Pat. No. 4,037,575, the pressure chamber, enclosed by the control pressure piston, is constantly connected with the pressure source by means of a throttle and thus is arranged to control with its front edge the connective diameter to a relief channel. This device has the disadvantage that, whatever pressure is selected in the pressure chamber, a more or less large amount of pressure fluid constantly flows off toward the relief side. This necessitates a powerful fuel supply pump for the fuel injection pump and an increased use of energy.